1. Field of Invention
The present invention generally relates to a light-emitting apparatus, and more particularly, to a flexible light-emitting apparatus with uniform brightness.
2. Description of Related Art
Since luminance of a light emitting diode (LED) has been increasing in recent years, the LED is gradually replacing a traditional light source in many fields. The luminance of the LED does not result from thermal light emission or electric discharge but from cold light emission, and therefore the life span of the LED is more than 100,000 hours. In addition, the LED also has advantages of highly short responsive time (about 10−9 S), small size, low power consumption, little pollution, high reliability, being adapted for mass production, and so on. Accordingly, the LED can be widely used in many fields. However, the LED is a point light source and has high directionality, so that light beams emitted from the LEDs are highly focused, and brightness of the LED is concentrated. Accordingly, applications of the LEDs are limited. Therefore, one of the main issues lies in how to guide the focused light beams uniformly as the LED light-emitting apparatus is highly developed.
FIG. 1 is a three-dimensional view of a flexible printed circuit board and LEDs of a conventional flexible LED neon lamp. Referring to FIG. 1, the conventional flexible LED neon lamp utilizes the flexible printed circuit board 50 to support the LEDs 60 with a single color or different colors. Moreover, the flexible printed circuit board 50 and the LEDs 60 are surrounded by a diffusion layer, so that the light beams emitted from the LEDs 60 are uniform.
However, since the flexible printed circuit board 50 is a plate, it is easy to be bended from a direction of the width parallel to an axis A1 to a direction D1, but it is not easy to be bended from a direction of the thickness parallel to an axis A2 to a direction D2. The flexibility of the conventional flexible LED neon lamp is thus highly limited due to the above-described phenomenon. Besides, since the LEDs 60 are only disposed on a surface 52 but not disposed on a surface 54, the light-emitting direction of the conventional flexible LED neon lamp is highly limited, so that applications and the flexibility of the conventional flexible LED neon lamp is significant restricted.